The end portions of optical waveguides must be arranged, for example in plug pins concentrically to their outer cladding surface, possibly with low eccentricity and angular displacement values. It must be possible to check the actual position of the optical waveguide in a ready-made plug pin (See for example Patent application DE-A No. 38 10 057.6).
In the manufacture of plugs the concentricity of the optical waveguide can be achieved in that the plug pin is aligned in such a way that the optical axis of the optical waveguide is aligned coaxially with an axis of rotation of a clamping device, after which the outer cladding surface of the plug pin can be cut coaxially with the optical waveguide and finished (See for example EP-A No. 207 552).
A method of the type described in the opening paragraph is known from GB-A 20 82 342. In this method the angular and lateral positions of an optical waveguide are adjusted relative to an axis of a lens. While the lateral position can be detected and readjusted by means of a four-quadrant diode, the angular position must be adjusted by observing the image of the short range field of a light beam passed through the optical waveguide. Complicated optical components are required for this purpose.